Process for weighting textile fibers and product obtained thereby



Patented Feb. 7, 1933 UNITED STATES PATENT OFFICE FRIEDRICH W. WEBER, OF EACKENSACK, NEW JERSEY, ASSIGNOB TO HAYWOOD CHEMICAL WORKS, OF HAYWOOD, NEW JERSEY, A CORPORATION OF NEW PROCESS FOR WEIGHTIN'G TEXTILE FIBERS AN D PRODUCT OBTAINED THEBEBY F0 Drawing.

My present invention relates to improvements in the art of treating fibers and particularly to the art of weighting silk and rayon, the object of the invention being to provide a process whereby both silk and rayon are quickly weighted with less labor and less danger to the operator, and whereby the metal oxides precipitated thereon are so intimately introduced into the fibers so as to give them an excellent whiteness and luster.

The demand of the public to have garments of silk improved in luster and the necessity of weighting rayon to improve the wearing of the light, loosely hanging rayon garments, make it desirable to provide a process which, without aflecting the strength of the fiber, will improve the luster and weight of other materials and provide these advantages at a relatively low price.

All processes introduced for this purpose were accompanied by a considerable number of difiiculties inasmuch as they were almost exclusively based on the application of tin tetrachloride and its conversion into tin phosphate on the fiber. These difiiculties were caused by the corrosive action of the tin tetrachloride solution and were most unpleasantly felt during its mechanical handling, but most important were the complications caused by its chemical pro erties displayed by the solution in the weig ting process proper. Y

The greatest difliculty in the weighting of the silk is caused by-acid and it is natural that up to now only the solutions of practically neutral or only weakly acid salts, as for instance of tin tetrachloride, SnCh, were found suitable for this purpose. Much hydrochloric acid is split off during the operation with tin tetrachloride and therefore the solutions of this salt, even if always used with certain precautions, became less and less 'efiective the longer they were used, on account of their enrichment with. ammonium chloride. 1

Application filed February 3, 1980. Serial No. 425,707.

This addition of ammonia became practlcally indispensable to establish the necessary bas1c1ty of the tin solution; but the ammonia applied for this purpose forms ammonium chloride and becomes in the long run a disturbing element and soon the weighting bath does not work properly any more and must be replaced.

In viewof the fact that also the efforts of the prior art of weighting silk by means of the insoluble compounds of the rare earth metals have not survived the experimental stage (see Heermann, Faerberei & Textilchemische Untersuchungen, publ. by Julius Springer, Berlin, 1923, p. 202) and as it is stated by Hottenroth, Artificial Silk, publ.

'by Pitman & Sons, London, 1928, on page 369, that r It is impossible to weight artificial silk 1n the manner adopted for natural silk, in WlllCh the weighting often amounts to several hundred per cent of the fiber. In so far as proposals for this purpose exist, they are confined to weighting up to 3 to 5-per cent or rarely up to 6 to 10 per cent.

the process of the present application is of all the greater importance because it furnishes not only silk and rayon products of absolute whiteness, but particularly furnishes rayon products showing the same increase in weight as natural silk.

With this situation confronting the silk weighting industry the 'problem solved by the present "invention was to, find'a deacidifying agent which could not only be used to de-acidify the metal salts of the hydrate, but it was without avail. More-- I over, the old rocesses always required considerable was ing to obtain a satisfactory hydrolytic splitting ofi of the tin as hydrate,- whereby great losses of tin were entailed.

It, therefore, represented a very beneficial contribution to the art when I actually discovered the circumstances under which it was possible to prevent right from the beginnm the quick increase in the acid content o the bath by the addition of a substance of such properties to simultaneously obtain a silk considerably increased 1n wei ht.

T e following points had to be considered in my efforts to improve the process:

' 1. The application of a weightingbath which is inclined to more quickly split off the tin oxy-hydrate without, however, liberating a considerable quantity of free acid and by preventing the formation of this acid for also savin a longer washin of the silk.

2. By t e application 0 a de-acidifying agent of high atomic weight and of a sufliclently low rice, but having at the same Y time an afiinlty to the silk at least as great uced acidity. My new invention also offers the advantage of applying asubstance which under certam circumstances displays or can be caused to display an aflinity to the silk fiber and therefore is also capable of being precipitated thereon.

I found that for instance a moderately concentrated tin tetrachloride solution may be de-acidified with carbonates of the rare earth metals without turning smoky, i. e. a considerable amount of mixed carbonates,

, or even the carbonate of one only, of the rare earth metals, for instance such as lanthanum didymium, thorium, etc., may be dissolve according to the following equations:

(2) amcoi-sngo- -aom in the tin tetrachloride, intended to be applied forweighting, by copiously generating carbon dioxide gas. The purposes intended to be attained by the application of these products and the phenomena accompanying the same will be explained below by way of example.

Example 1 If for instance 75 grams of thorium carbonate are slowly addedto 7 grams of a 50 B6. tin tetra-chloride solution, heated up to 75 (3., they will be quickly dissolved. entirely and the solution obtained will show only a faint smokiness which is due to small traces of impurities of the applied thorium carbonate or to those of tin tetrachloride and by filtration 'or which can be removed either decantation.

The solution thus obtained is immediately ready for application and has only to be adjusted to 36 B. to have the proper concentration, The silk is allowed to soak in this tin-thorium oxychloride solution for some time, for instance 14% hours; it is then taken out, the surplus of the solution is thoroughly squeezed out of the silk and the same is then washed with relatively little water. The washed silk is then introduced into a di-sodium phosphate bath having a temperature of approximately C. The silk is allowed to hang therein also for 1 hours, taken out, washed and dried. This procedure may be repeated once or twice, or as often as desired. The increase in the weight of the silk obtained in its first passage through the bath is considerably greater than withany other solution known in the art of silk weighting up to now.

From former-experiences one would logically suppose that such a solution will turn smoky when allowed to stand, or by the repeated passage of the silk through this solution would lose considerably in its concentration, or would otherwise be considerably disturbed in its composition, but this is in no wise the case.

Such permanently clear solutions require, however, that the water be free of certain salts which eventually may precipitate, for

instance calcium and iron salts. s the water supply in the silk dyeing plants often does not meet this condition, I may operate the process as described in the following:

Ewmnple Q I introduce 7 50, gr. SnCl, solution, 50 B., into a vessel and heat it approximately up to C.,-whereupon I add 50 gr. of the carbonates of lanthanum and didymium while the solution is agitated. The mixture is heated for some minutes after all the carbonate has dissolved, whereupon water is added to make up 1 liter and the solution is c then allowed to cool. Gradually a more or less brown preci itate segregates which is filtered ofi where y an absolutely clear solution is obtained, to which. I add a certain amount of an organic acid which forms a soluble calcium and iron salt; such acids are practise in my new process.

for instance, formic acid, acetic acid, and similar acids low priced enough and fulfilling the above stated requirements concernin the solubility of its calcium and iron salt. add for instance to the above quantity of solution 10 gr. of a 98% formic acid or a corresponding amount of any of the other acids. After this last addition the solution shows 31 B. and is ready for use.

The solutions obtained by the directions of aforesaid examples are particularly suitable for weighting both natural and artificial silk, regardless whether'the latter were products of the viscose, the cuprammonium-cel'lulose, the cellulose acetate or other process, ,which products I simply embrace henceforth in the general term rayon.

The above given examples are, moreover, typical only of the variations which I may It is evident that its simplicity will allow even the operation by a working man, having no chemical training, after a short instruction.

As I already stated above the tin tetrachloride solution, de-acidified by the carbonates of the rare earth metals, would stay clear even without the addition of the acid, but the pres-= ence of the same has the considerable advantage, in case of the presence of Ca, or Fe compounds, to prevent their precipitation upon the silk which would render the silk unsightly and thus cause the loss of the silk because these defects can never be remedied.

The new process offers therefore the best possibility of weighting silk with a relatively highly concentrated solution without appreciable losses of tin and with a highly desirable luster.

The tendency of the solution, thus obtained, to precipitate upon silk 'is much stronger than that of any other solution heretofore applied for the same purpose. This appears due to the fact that the solution after its treatment with the rare earth metals contains the same original amount of acid, but that of this acid a' part only is still combined with the tin, while a considerable balance of acid has combined with the rare earth metals, the result being that the solution of the tin and of the rare earth metals shows a very much weak ened acid reaction. When the de-acidified solution enters the capillary spaces of the fiber it is hydrolyzed; the solution in said spaces thereby turns rapidly more basic and also easily precipitates the hydrate of stannic acid. fiber already charged with tin oxyhydrates shows great aflinity for a deposit of the oxy-hydrates of the rare earth metals.

In this process the fortunate result occurs that simultaneously a precipitation of tin oXy-hydrate and of those of the rare earth metals takes place in one treatment, or operation, in the same bath without any disturbance of its quantitative composition i e. in the proportion of its ingredients.

is, this fortunate combination the present invention offers a distinct advantage over the prior art.

The advantage of my new process over the old tin-tetrachloride process is self evident to one skilled in the art. He finds that without any addition whatever he can obtain for three times in succession, each time with a new skein, the same amount of increase in the weight of the fiber which would be entirely impossible in the SnCl, baths of the prior art on account of its getting continuously more acid. This and similar advantages will soon be apparent to the silk dyer, and particularly that the application of solutions of relatively low acidity harbors less danger to the durability of the fiber.

Also the possibility of using highly concentrated solutions right from the beginning and the great stability of the composition, resulting in a constant clearness, of these highly basic solutions will be appreciated, as well as an immediate increase in weight of the fiber in the double proportion of that 0b- 7 treated as described, that therefore this phosphate solution is also better utilized, that the completely weighted product appears to be more voluminous particularly if thorium is applied, and that the produced silk and rayon is always whiter and of greater durability because the conditions for the formation of metastannic acid are removed.

Another advantage, which must be particularly emphasized, is the constant clearness of the solution and that thereby the obtained product is whiter and more lustrous,

which is not the case if for instance thorium is applied underother conditions, or if silk is treated only with tin phosphate.

My new process described above is also applicable to other metal solutions used as mordants in the treatment of fibers for dyeing purposes and solutions of iron chloride, F e01 and similarly acting salts of the aforesaid and other metals may be treated according to the principle of my new process for various purposes of treating textile fibers, i. e., in place of tin with, for instance, the correspondingly deacidified solutions of iron, aluminum, etc. salts.

The new process brings relief from the various, sorely felt hardships of the tin-tetrachloride bath because the corrosive effect of the same was almost equally as destructive structive to the hands and body of the operator. All these hardshi s are at least reduced to a tolerable degree, i not entirely avoided by my new process.

Moreover, the whole process is more simple, a few steps only being required to obtain a better effect than with tin tetrachloride alone. The simplicity of the whole process speaks for itself and the operation and eontrol of the process can be done by any plain laborer after being once instructed, for a little more of added carbonates of the rare earth metals is far less disturbing than the increase in acid of the tin tetrachloride bath.

This simplicity avoids the close observation which had to be-given to each separate tin tetrachloride bath and the many analytical tests to follow up the exhaustion of these baths and the effect of the addition of ammonia on the same.

It is one of the desirable features of my invention that the de-acidification of the tintetrachloride solution and similar salt solution is effected with a material which in itself is capable of adding weight to both natural and artificial silk; forjnstance if I apply 7 the carbonate of thorium, which has the high mantles for incandescent gas light,

a their compounds, the manufacturers always have to separate the thorium from the monazite sand and for the present state of the lighting industry the stocks of thorium compounds were ever increasing and swallowing more capital, so that also in this field my new invention brings relief.

Whenever I speak of an alkali. metal salt for acting on the basic tin and on the basic rare earth metal salt, I also mean to include the corresponding ammonium salt .in the term alkali metal salt.

What I claim isf 1. The process of weighting textile fibers, said process consisting in acting upon a weighting metal salt solution with the comound of a'rare earth metal capable of com- Eining with the acid component of aforesaid metal salt thereby obtaining a practically clear solution of the reaction products, passing the fiber through the solution of the reaction products, washing the fiber thus treated with water, and then passing the fiber through the solution of a salt capable of forming an insolublesalt with each of the metals introduced into the fiber.

2. The process of weighting textile fibers, said process consisting in acting upon a weighting metal salt solution with the carbonate of a rare earth metal thereby obtaining a practically clear solution'of the reaction products, passing the fiber through the solution of the reaction products, washing the fiber thus treated, and then passing the fiber through the solution of a salt forming an insoluble salt with each of the metals introduced into the fiber.

3. The process of weighting textile fibers, comprising acting upona weighting metal salt solution with the compound of a rare earth metal capable of combining with the acid component of aforesaid metal salt thereby obtaining a practically clear solution of the reaction products, and subjecting the fiber to said clear solution.

4. The process of weighting textile fibers, comprisingvacting upon a weighting metal salt solution with the carbonate of a rare earth metal obtaining thereby a practically clear solution of the reaction products, and subjecting the fiber to said clear solution.

5. The process of weighting both natural and artificial silk, said process consisting in acting upon a tin tetrachloride solution with the compound of a rare earth metal capable of combining with the acid component of aforesaid tin tetrachloride solution and thereby obtaining a practically clear solution of the reaction products, passing the silk through the solution of the reaction products,

washing the silk thus treated with water, and then passing the silk through the solution of a salt capable of forming an insoluble salt with the -tin and the rare earth metal introduced into the fiber.

6. The process of weighting both natural and artificial silk, said process consisting in acting upon a tin tetrachloride solutionwith the compound of a rare earth metal ca able of combining with the acid component of aforesaid tin tetrachloride solution andthereby obtaining a practically clearsolution of the reaction products, passing the silk through the solution of di-sodium phosphate.

7. The process of-weighting both natural and artificial silk, said rocess consisting in acting upon a tin tetrachloride solution with the carbonate of a rare earth metal thereby obtaining a practically clear solution of the reaction products, passing the silk through a solution of the reaction products, washing the silk thus treated with water, and then passing the silk through the solution of a salt capable of forming an insoluble salt with the tin and the rare earth metal introduced into the fiber.

8. The process of weighting both natural and artificial silk, said process consisting in acting upon a tin tetrachloride solution with the carbonate of a rare earth metal thereby obtaining a practically clear solution of the react-ion products, passing the silk through the solution of the reaction products, washing the silk thus treated with water, and then passing thc silk through a solution of disodium phosphate.

9. The process of weighting both natural and artificial silk, said process consisting in acting upon the solution of a metal salt, suitable as a weighting material for silk, with .a thorium compound, capable of combining with the acid component of said metal salt, thereby obtaining a practically clear solution of the reaction products, passing the silk through this solution of the reaction products, washing the silk thus treated with water, and then passing the silk through a solution forming an insoluble salt with aforesaid metal and thorium.

10. The process of weighting both natural and artificial silk, said process consisting in acting upon the solution of a metal salt, suitable as a weighting material for silk, with thorium carbonate thereby obtaining a practically clear solution of the reaction products, passing the silk through this solution of the reaction products, washing the silk thus treated withwater, and then passing the silk through a solution formin an insoluble salt with aforesaid metal and t orium.

11. The process of weighting both natural and artificial silk, said process consisting in acting upon a solution of tin tetrachloride with thorium carbonate, thereby obtaining a practicall clear solution of the reaction products, passing the silk through this solution of the reaction products, washing the silk thus treated with water, and then passin the silk through a solution forming an inso uble salt with aforesaid metal and thorium.

12. The process of weighting both natural and artificial silk comprising deacidifying a metal salt solution, having weighting properties, by a carbonate of a rare earth metal, thereby obtaining a clear solution of the reaction products, and subjecting the silk to said clear solution. a

13. The process of weighting both natural and artificial silk comprising deacidifying a metal salt solution, having weighting properties by thorium carbonate, thereby obtaming a clear solution of the reaction products and subjecting the silk to said clear solution.

14. The process ofweighting both natural and artificial silk comprising deacidifying tin-tetrachloride solution with a basic compound of thorium, thereby obtaining a practically clear solution of the reaction products, and subjecting the silk to said clear solution.

15. .The process of weighting both natural and artificial silk comprising deacidifying tin tetrachloride solution with thorium carbonate, thereby obtaining a clear solution of the reaction products, and subjecting the silk to the said clear solution.

16. The method of weighting both natur and artificial silk com rising acting on the silk with a solution of basic metal chlorides, one of the same bting a basic tin chloride salt.

17. The method of weighting both natural and artificial silk comprising acting on the silk with a solution of tin tetrachloride deprived of its deleterious effect by the action of a thorium carbonate.

18. As a base for the weighting of both natural and artificial silk, an aqueous solution of a basic tin chloride and of a basic rare earth metal chloride.

19. As a base for the weighting of both nat; ural and artificial silk, an aqueous solution of a basic tin chloride and of a basic thorium chloride.

20. The process of weighting textile fibers, said process consisting in acting upon a weighting metal salt solution with a weighting metal compound capable of combining with part of the acid component of aforesaid metal salt, adding to the reaction product an organic acid capable of forming soluble salts with all metals present in the reaction mixture, passing the fiber through the solu tion of the reaction products, then passing the fiber thus treated through the solution of a substance capable of forming an insoluble salt with each of the metals mtroduoed into the fiber.

21. The process of weighting textile fibers, said process consisting in acting upon a weighting metal salt solution with a compound of a rare earth metal capable of combining with the acid component of aforesaid metal salt, adding to the reaction product an organic acid capable of forming soluble salts with all metals present in the reaction mixture, passing the fiber through the solution of the reaction products, then passing the fiber thus treated through the solution of a substance capable of forming an insoluble salt Egth each of the metals introduced into the 22. The process of weighting both natural and artificial silk fibers, said process consisting in acting upon a tin-tetrachloride solution with a compound of a rare earth metal capable of combining with the chlorine of the tin tetrachloride and thereby dissolving in said solution, adding to the reaction product an organic acid forming a soluble salt with aforesaid metals and with calcium and iron present in the water applied for the solution, passing the silk through the solution of the mixture, and then passing the silk through a solution capable of forming an insoluble salt with the tin and the rare earth metal introduced into the silk.

' 23. The process of weighting both natural .lution with a I mixture ofthe carbonates of lanthanum and didymium, adding formic acid to the reaction product, passing the silk through the solution of the mlxture, and then 1 5 gassing the silk through a solution capable of orming an insoluble salt with the tin, lanthanum and didymium.

24 In the grocess as described b claim 22,

the step of a ding formic acid to t e solution 1-0 of tin tetrachloride de-acidified by rare earth metals. 4

-- In witness whereof, I have hereunto set my hand. a

FRIEDRICH W. WEBER. 

